pellmell I think this is open to interpretation.
First, must not be too easy for a player to make adjustments. What does that mean? I suspect they're talking about "ripping a piece of lead tape off," and not "taking out a screw and wrench and putting a new weight in or switching to a new weight while on the course." That doesn't seem to be "too easy."
Second, that the mechanism _must be firmly fixed." Well, if there is no "mechanism" inserted, there's not much chance it will work loose, is there?
Your honour, my client was in compliance with the rules. I rest my case.